AN 977: Nios® V Processor Custom Instruction

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ID 773194
Date 4/14/2023
Public
Document Table of Contents
Document Table of Contents x
1. Nios® V Processor Custom Instruction Overview 2. Custom Instruction Hardware Interface 3. Custom Instruction Software Interface 4. Designing with Intel® Quartus® Prime and Platform Designer 5. Document Revision History for AN 977: Nios® V Processor Custom Instruction
1. Nios® V Processor Custom Instruction Overview x
1.1. Implementing Custom Instruction 1.2. Implementing Custom Instruction Logic Block 1.3. Implementing Custom Instruction Software
2. Custom Instruction Hardware Interface x
2.1. Custom Instruction Types 2.2. Multicycle Custom Instructions 2.3. Extended Custom Instruction 2.4. External Interface Custom Instructions
2.2. Multicycle Custom Instructions x
2.2.1. Multicycle Custom Instruction Ports 2.2.2. Multicycle Custom Instruction Timing 2.2.3. Implementing Combinational Custom Instruction
2.3. Extended Custom Instruction x
2.3.1. Extended Custom Instruction Timing
3. Custom Instruction Software Interface x
3.1. Custom Instruction Software C Macro 3.2. Custom Instruction Assembly Language Interface 3.3. Custom Instruction Word Format
3.2. Custom Instruction Assembly Language Interface x
3.2.1. Custom Instruction Assembly Language Syntax
3.3. Custom Instruction Word Format x
3.3.1. Selector and Extension Indexes 3.3.2. ALU Switch 3.3.3. User-defined Immediate Software C Macros with funct3 and funct7 fields assigned with "x"
4. Designing with Intel® Quartus® Prime and Platform Designer x
4.1. Interface Signals 4.2. Custom Instruction Manager 4.3. Custom Instruction Subordinate
4.1. Interface Signals x
4.1.1. alu_result port 4.1.2. ctrl port
4.2. Custom Instruction Manager x
4.2.1. Hardware Interfaces Table 4.2.2. Software C-Macro Table
4.3. Custom Instruction Subordinate x
4.3.1. Writing the Custom Instruction HDL File 4.3.2. Opening the Component Editor 4.3.3. Specifying the Custom Instruction Component Type 4.3.4. Displaying the Custom Instruction Block Symbol 4.3.5. Adding the Custom Instruction HDL File 4.3.6. Configuring the Custom Instruction Parameter Type 4.3.7. Setting Up the Custom Instruction Interfaces 4.3.8. Saving and Adding the Custom Instruction 4.3.9. Generating and Compiling the Processor System
1. Nios® V Processor Custom Instruction Overview
2. Custom Instruction Hardware Interface
3. Custom Instruction Software Interface
4. Designing with Intel® Quartus® Prime and Platform Designer
5. Document Revision History for AN 977: Nios® V Processor Custom Instruction

3.3.3. User-defined Immediate

You can apply the funct7 or funct3 field as a user-defined immediate by assigning “x” in the Software C-Macro, in the Platform Designer. Assigning the logic translates the fields into input arguments in the Software C-Macro.

Note: Platform Designer translates the bit field to the user-defined immediate when assigning the logic "x" in Software C-Macro only.

Software C Macros with funct3 and funct7 fields assigned with "x" 

#define CUSTOM_OPERATION(VAL_1, VAL_2, F3, F7) ({ \
 int output; \
 asm volatile (".insn r 0x2B, %[FUNCT3], (0x0 | (%[FUNCT7]<<0)), %[out], %[input1], %[input2]" \
    : [out] "=r" (output) \
    : [input1] "r" (VAL_1), [input2] "r" (VAL_2), [FUNCT3] "i" (F3), [FUNCT7] "i" (F7)); \
    output;  \
})
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